Problem A. 649. (September 2015)

A. 649. A convex polyhedron has only quadrilateral faces. Show that it is possible to split every face into two triangles by drawing one of its diagonals in such a way that at each vertex of the polyhedron, an even number of triangles meet.

Proposed by: János Nagy, Budapest

(5 pont)

Deadline expired on October 12, 2015.

Statistics:

5 students sent a solution.
5 points:	Bodnár Levente, Lajkó Kálmán.
1 point:	1 student.
0 point:	2 students.

Problems in Mathematics of KöMaL, September 2015